1. Field of the Invention
The present invention relates to a photometric operation system of a camera in which photometering and calculating operations can be carried out for a plurality of object areas (focusing areas).
2. Description of the Related Art
In a camera having a zoom lens or multi-focus lens as, such a photographing lens, in which the brightness (luminance) of an object to be photographed is measured by a photometering optical system separate from the photographing lens, without passing through the photographing lens, if the focal length of the photographing lens changes, no change in the light receiving area occurs. To measure the brightness of the object within an object area corresponding to the focal length of the photographing lens, i.e., the photographing range, it is known to measure the brightness of objects within object areas of different sizes.
However, split photometering elements for a plurality of split photometering areas are complicated, thus resulting in a complex calculating operation. Moreover, in a photometering system having two photometering areas in conventional cameras, a spot metering mode or an averaged overall light reading mode can be selected, but the same photometering operation is carried out regardless of the focal length, i.e., it is impossible to vary the photometric distribution in accordance with the focal length.
It is an object of the present invention to provide a photometric operation system of a camera having a photographing lens having a variable focal length, such as a zoom lens and a photometering mechanism in which photometric data can be obtained from a plurality of photometering zones (focusing zones), and appropriate photometric data corresponding to the focal length can be obtained.